1. Field of the Invention
The invention relates to a recycling method and a treatment device for a battery pack, and more specifically, to a recycling method and a treatment device for a battery pack that make it possible to safely perform an operation of recycling the battery pack.
2. Description of Related Art
In general, a battery pack is composed of an assembled battery, which is constituted by connecting in series a plurality of (e.g., about 10) battery modules, each of which is a single component unit obtained by connecting in series a plurality of (e.g., about 6 or 8) battery cells of a secondary battery such as a nickel hydrate secondary battery, a lithium-ion secondary battery, or the like to one another, to one another, electronic components such as a control unit that monitors and controls a charge state of the battery modules, a relay for disconnecting an electric circuit, a safety plug for mechanically cutting off the circuit, a cooling blower that cools the assembled battery, and the like, signal lines and power lines that connect the respective components to one another, a case that accommodates them in a sealed manner, and the like.
In the case where such a battery pack is used as, for example, a component for a vehicle such as a hybrid vehicle or the like, when the vehicle is scrapped, the battery pack is removed from the vehicle. After an operation of dismantling the battery pack and sorting the battery cells from the other components is performed, useful metals are recovered from the battery cells.
In general, a battery pack used as an automobile component generates a high voltage (e.g., a voltage equal to or higher than 300 V). Even when the vehicle is scrapped and the battery pack is removed therefrom, the battery pack is often held at the high voltage. In general, the operation of dismantling the battery pack and sorting the battery cells from the other components is manually performed by an operator who wears protective equipment such as insulated gloves or the like. Therefore, the securement of operational safety needs to be sufficiently taken into account.
Further, with a view to enhancing the safety in performing the operation of dismantling the battery pack and the like, it is also conceivable to discharge the assembled battery in the battery pack. In this case, however, the battery pack needs to be stored for a long time for self-discharge or to be forcibly discharged through the use of a resistor or the like. Consequently, the operation of recycling the battery pack takes a long time or becomes troublesome.
Thus, from the standpoint of ensuring the safety in performing the recycling operation and reducing the time required for the recycling operation, it is desirable that the assembled battery in the battery pack be swiftly and safely insulated (0 V).
Further, as an electrolytic solution in the battery cells, a burnable organic electrolyte is used in the case of a lithium-ion secondary battery, and a water-soluble electrolyte is used in the case of a nickel hydride secondary battery or the like. In performing the recycling operation, the recycling of the battery pack can be substantially facilitated by efficiently removing the electrolytic solution in the battery cells.